Expert or advocate? Where the courts draw the line

Expert testimony can provide invaluable assistance to a case. By its very nature, it provides the trier of fact with insight that it would not otherwise have and can make your case. However, an expert who crosses the line into advocacy can ultimately do more harm than good. Two recent decisions provide lawyers, insurance adjusters and the public with an idea of how the court will respond to experts who become advocates for one party or the other.

A B.C. example – advocacy goes to weight

In Thompson v Helgeson 2017 BCSC 927, the plaintiff was seeking damages for injuries she sustained in a motor vehicle accident. Justice Sewell found she had suffered some whiplash-type soft-tissue injury, headaches, structural damage to the tissues of her spinal column, and a brain injury. He also had to assess whether she had any psychiatric illness as a result of the accident. He heard opinion evidence from a psychiatrist called by the plaintiff and a psychiatrist called by the defendant. The two psychiatrists disagreed as to whether the plaintiff suffered any psychiatric disorders.

Sewell J. held that both the doctors were “somewhat partisan in their opinions” and that both of the doctors’ reports were adversarial in their tone and content. He found that the psychiatrist called by the defendant was “argumentative and at times non-responsive” in his answers on cross-examination. In the end, the court gave no weight to either of their reports as the plaintiff’s psychiatrist “was going out of his way to identify every possible mental illness suggested by Ms. Thompson’s reported symptoms,” while the defendant’s psychiatrist “seemed anxious to convey the impression that Ms. Thompson was in no distress whatsoever.”

Sewell J. also held that neither report was helpful as he did not need to know whether the plaintiff “meets the criteria for specific psychiatric disorders set out in the DSM 5. In assessing damages, the question is whether Ms. Thompson’s symptoms are genuine, whether there is a substantial connection between those symptoms and the defendant’s negligence, and the effect that those symptoms have had on the plaintiff.”

It is important to note that Sewell J. did not cite White Burgess and did not go through a White Burgess analysis to determine whether the experts’ testimony was admissible. His reasons do not indicate whether either of the parties objected to the expert evidence.

The Ontario position – advocacy leads to exclusion

In Bruff-Murphy v Gunawardena 2017 ONCA 502, the plaintiff appealed the decision of Justice Paul Kane, where he “qualified an expert to testify on behalf of the defence despite some very serious reservations about the expert’s methodology and independence.” The trial judge had concerns that the defendant’s expert had “crossed the line from an objective witness to an advocate for the defence.” However, the trial judge did nothing to exclude the opinion evidence or warn the jury about the issues with the expert’s testimony. The jury returned a verdict assessing general damages at $23,500 and rejected all other heads of damages. The plaintiff appealed the trial decision.

At trial, the plaintiff objected to the testimony from the defendant’s psychiatrist. The plaintiff argued that the expert’s report was essentially an attack on the plaintiff’s credibility as the expert had pointed to inconsistencies in the plaintiff’s interview with Dr. Bail and the plaintiff’s medical records without putting those inconsistencies to the plaintiff for clarification, thus violating the rule in Browne v Dunn (1893) 6 R. 67 (H.L.). The plaintiff also argued that expert was biased and that her counsel should be allowed to cross-examine the expert on two other unrelated cases where he was found to not be an independent witness.

The trial judge held that the cross-examination on the expert’s prior testimony in unrelated cases was inappropriate but also held that the expert could not testify on certain sections of his report where he was critical of the plaintiff’s credibility. After closing submissions, the trial judge briefly reviewed the expert’s testimony and did not instruct the jury about the duty of an expert witness, nor did he “raise any concerns with respect to the substance of [the expert’s] testimony or his independence.”

In a subsequent decision on a threshold motion brought by the defendant, the trial judge included an analysis of the concerns he had with the expert’s evidence but he “permitted [the expert] to testify because of the ‘[v]ery high threshold’ [that must be met] before a court may exclude expert testimony for bias” as established by the Supreme Court of Canada in White Burgess Langille Inman v Abbott and Halliburton Co. 2015 SCC 23.

Hourgan J.A. in the Ontario Court of Appeal ordered new trial on the grounds that the trial judge erred when he failed to prevent the expert from testifying and, after the expert’s testimony delved into advocacy, did not not exclude the unacceptable evidence. He cited the two-step analysis required by the Supreme Court in White Burgess to assess the admissibility of expert evidence. The first step, or threshold requirements, are the four factors set out in R. v Mohan 1994 2 SCR 9:

Relevance

Necessity in assisting the trier of fact

Absence of an exclusionary rule

The need for the expert to be properly qualified

The second step is a “discretionary gatekeeping step” where “the judge balances the potential risks and benefits of admitting the evidence in order to decide whether the potential benefits justify the risks.”

Hourgan J.A. held that the trial judge erred when he stopped his analysis after finding that the expert’s evidence met the Mohan requirements and appeared “to have believed that he was obliged to qualify Dr. Bail once he concluded that the witness met the initial Mohan threshold.” He held that this was not correct, saying that the “potential risks of admitting [the expert’s] evidence far outweighed the potential benefit of the testimony. It was evident from a review of [the expert’s] report that there was a high probability that he would prove to be a troublesome expert witness, one who was intent on advocating for the defence and unwilling to properly fulfil his duties to the court.” The trial judge’s decision not to exclude the testimony was an error of law requiring a new trial.

Guard against expert advocacy

Both of these cases show that partisan evidence from an expert can have a significant effect on the outcome of a trial. In Thompson v Helgeson , the trial judge simply chose to give no weight to the expert evidence, essentially rendering the opinions a nullity. In Bruff-Murphy v Gunawardena, the court overturned a jury verdict and ordered a new trial.

Clients, and their lawyers, should consider whether it is more harmful than helpful to tender an expert opinion when that opinion cannot hold up to scrutiny. Experts’ reports should be reviewed with a critical eye not just for the overall opinion but for how the opinion was reached, the expert’s tone, and the expert’s restraint in ensuring that the report complies with the requirements that it not advocate for one side or the other.

During preparation, counsel should examine the expert’s answers carefully to see whether the evidence is worth leading. At trial, the effect of having improper expert evidence excluded, rather than being admitted and considered later for “weight,” should be underscored. The decisions in White Burgess and Bruff-Murphy are a reminder that the judge is a gate-keeper and is there to decide on evidentiary matters.